1. Field of the Invention
This invention relates to the field of Holter Monitoring and, more specifically, to the analysis and display of the QRS intervals and associated pacer signals on an electrocardiograph.
1. Description of the Prior Art
The prior art has dealt with the need for the detection of pacemaker signals within an electrocardiogram and with the display of a large number of QRS signals by means on an electrocardiograph. Such a system was taught by U.S. Pat. No. 4,336,810 issued to Anderson et al. and included features such as scanning Holter tapes at high speed to produce Holter displays and an associated proprietary electrocardiograph termed the ARRHYTHMIAGRAPH. The ARRHYTHMIAGRAPH.TM., which is a trademark of the assignee of Anderson et al., presently is known to appear graphically on the side or bottom of an ECG display to depict ectopic patterns as well as changes in rate and rhythm by usage of a series of bar graphs where each bar represents the length of time from one QRS to the next QRS. The ARRHYTHMIAGRAPH has proven useful in providing a means of surveying a large number of categorized heartbeats simultaneously. However, the ARRHYTHMIAGRAPH has until the present time has only been used with naturally occurring ECG signals and has not been shown to be useful with respect to pacemaker signals.
U.S. Pat. Nos. 4,291,703 and 4,532,934 issued to Kelen, each presented a system that permitted recording and analysis of heartbeats as well as pacemaker generated pulses. While successful in detecting pacemaker signals this system did not satisfy the need for graphically viewing large numbers of pacemaker signals in relation to QRS intervals.
Various types of pacemakers are available today. Among these are pacemakers which provide for either atrial stimulus, ventricular stimulus or both. Pacemakers are also currently available with defibulators. Electrocardiographic systems that analyze human subjects who have pacemakers must, therefore, have the capability of identifying various types of electronic signals that can originate within a pacemaker. Unfortunately, conventional systems currently available can not provide analysis results of affects pacemakers signals have on QRS intervals in a manner that is visually discernible over a large number of beats.
As can be seen by the foregoing discussion, there remains a need within the prior art for a system that can provide analysis results of pacemakers signals effect on QRS intervals that are visually discernible simultaneously over a large number of beats. The present invention not only identifies various pacemaker signals, it presents an ARRHYTHMIAGRAPH displaying 360 QRS cycles and analyzes the affect of pacemaker signals on the QRS cycle. The present invention addresses the shortcoming of the aforementioned prior art in that it provides a manner by which large numbers of pacemakers signals can be viewed to identify their relationship to the relative QRS cycles.